GEOLOGY AND PALEONTOLOGY OF THE SCHOHARIE VALLEY 339 



sents the inner lowland. As will be seen presently this region 

 does not represent a cuesta in its primitive condition, but rather 

 a revived eueistalike topography. 



If, with continued recession of the inface of the cuesta, and a 

 widening of the inner lowland, a second hard stratum is discov- 

 ered beneath the soft one, the inner lowland may for a time be 



Fig. 211 Diagram of simple escarpment formed by exposed hai'd stratum (3) overlying- a 



soft stratum 



floored by this stratum. Gradually however this stratum will 

 also be cut through and if another softer one is discovered be- 

 neath, a second inface will soon come into existence, the cuesta 

 now becoming a double one [fig. 211, 212]. The retreat of both 

 cliffs may be uniform or there may be a differential retreat. In 

 the first case the two cliffs will never be far apart, in the second 



Fig. 213 Compound escarpment produced by two hard strata after recession to dotted 



line in fig. 211 



case they will either approach each other, the lower one gaining on 

 the upper, or become more and more separated, the upper one 

 retreating faster. Cliff's of differential retreat are well illustrated 

 by the terraces on West hill (plate 1). 



Where there is a regular alternation of hard and soft strata 

 several tinies repeated, the cuesta front will be terraced, but it 

 will be essentially one cuesta front or inface, just as the eastern 

 face of West hill is a single one, though composed of several 



